xfs: xfs_buf_iomove() doesn't care about signedness

xfs_buf_iomove() uses xfs_caddr_t as it's parameter types, but it doesn't
care about the signedness of the variables as it is just copying the
data. Change the prototype to use void * so that we don't get sign
warnings at call sites.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 9a29d18..4f2ad66 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -243,7 +243,7 @@
 extern void xfs_buf_ioerror(xfs_buf_t *, int);
 extern int xfs_buf_iorequest(xfs_buf_t *);
 extern int xfs_buf_iowait(xfs_buf_t *);
-extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, xfs_caddr_t,
+extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
 				xfs_buf_rw_t);
 
 static inline int xfs_buf_iostrategy(xfs_buf_t *bp)